The objective of this research is to examine epidemiologic associations of body fatness, insulin resistance, lipids, and LVM and test the hypothesis that body fatness and insulin resistance during adolescence predict levels of adiposity, insulin resistance, lipids, left ventricular mass, and systolic blood pressure in young adulthood. The study will be conducted in a cohort of 200 subjects recruited at mean age 13 years from the top 15% of the blood pressure distribution in a general population, and reevaluated at age 17 years. Previous studies in this cohort at age 13 have shown a difference between males and females in the response of LVM to increase in body size; and a segregation analysis at age 17 in the cohort and their parents has inferred the presence of a major gene influencing the levels of fasting insulin. Therefore, a second objective of this research will be to define gender differences in the association of left ventricular mass in young adulthood with cardiovascular risk factors in adolescence; and a third objective is to confirm the genetic results when the participants are young adults and share less of the childhood familial environment with their parents. At the GCRC participants will have a euglycemic insulin clamp performed, and fasting serum analyzed for lipids and IGF-1 measurements.